In the human body, exercise makes everything work. Without exercise there is no movement, and therefore, there is no life.
Are you worried about proper nutrition? No matter what you eat your body can't use any of it if the muscles don't move it around the body.
Exercise is a basic key to health.
When you exercise you automatically make other healthy choices. You drink more water, you breath more deeply, you crave good food to eat.
Basic rules for exercise:
Work up to exercising for 45 minutes to an hour 5 or 6 days a week.
Increase gradually, not all at once.
Never do the exact same exercise two days in a row.
Always have one day a week as a rest day (the Sabbath).
Breath deeply while exercising. Be sure to blow all the air out of your lungs.
Drink a cup or two of water before each exercise session.
Start slowly until the body gets warmed up, then you can go harder.
In the end of the workout do some good smooth stretching as you cool down.
Protein both before and after exercise can help build strong muscle.
Carbohydrates provide most of the energy for exercise, don't skimp on them.